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How trying to pedal like a pro can be a waste of energy

Oxford researchers find that higher cadences are inefficient at lower power outputs

Professional cyclists tend to pedal at very high cadences, frequently over 100 revolutions per minute, as this proves to be more efficient. However, Medical Daily reports how Oxford University researchers have found that such an approach is much less effective for recreational cyclists.

Dr Federico Formenti, who led the study, explained that the team was looking at how VO2 max was estimated when using a stationary bike. Currently, calculations are based on body mass in kilograms and work rate in watts, but the team wanted to see if including pedalling speed – cadence – would produce more accurate results.

The study participants were ten healthy men aged between 19 and 48. Their energy consumption was measured at different cadences and exercise intensities, while video-based motion analysis was employed to study the mechanical determinants of changes in energy cost.

Formenti said that at very low intensities, a large proportion of the energy used in pedalling quickly goes on nothing more than spinning the legs.

“We used mathematical models to show the degree to which energy required to spin the legs increases with cadence. At a low exercise intensity of 50 watts, a recreational cyclist trying to pedal like a professional at 110 revolutions per minute will use more than 60 percent of their power just to spin their legs. Only 40 percent is going into overcoming the cycling resistance. To translate that to cycling on the road – only 40 percent of the energy you burn would be going into moving the bike forward.”

Based on their findings and other published results, Formenti and colleagues have proposed a new and more accurate equation for estimating energy consumption on stationary bikes, factoring in cadence as well as the rider’s weight and the power they produce.

“Recreational cyclists want to pedal efficiently, just like the professionals do, but achieving that means pedalling differently from the professionals. Pedalling faster might work for Tour de France winners, but it probably won't work for the rest of us. At low exercise intensity, increasing cadence mostly results in a less effective stroke, reducing efficiency.”

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32 comments

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vonhelmet | 8 years ago
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My knees would fall off if I went everywhere at 50rpm.

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leewalton | 8 years ago
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I would have thought at 85W the tests are going to be practically meaningless, as trying to keep the stroke even with light resistance will be more difficult I would think, leading to a loss in efficiency.

My average cadence tends to be about 90 RPM when I'm on a ride, but when just pootling about, and hence lower power, unsurprisingly I drop the cadence.

 7

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Judge dreadful | 8 years ago
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I usually manage to get where I'm going in a decent time, up hills, down hills, long(ish) distances, short distances. I've never needed more than 40-50 RPm. I chuckle to myself even more when I pass the hamsters 'spinning' up the hill, at half their 'cadence'. That's the beauty of having mostly ridden single speeds / fixies for years I guess.

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Darren C replied to Judge dreadful | 8 years ago
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Judge dreadful wrote:

I usually manage to get where I'm going in a decent time, up hills, down hills, long(ish) distances, short distances. I've never needed more than 40-50 RPm. I chuckle to myself even more when I pass the hamsters 'spinning' up the hill, at half their 'cadence'. That's the beauty of having mostly ridden single speeds / fixies for years I guess.

Some of us naturally have high cadences, I average @103 RPM, so 80+ uphill is normal for me, also gained from fixed wheel riding, partly from the velodrome. They are probably having a chuckle at you too for looking like a 'pig stuck in mud' with your low cadence.
We are all unique, and what works for one person won't necessarily work for another, there is no right speed/cadence that fits all just what works best for you!

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DaSy replied to Judge dreadful | 8 years ago
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Judge dreadful wrote:

I've never needed more than 40-50 RPm.

I'm not sure I'd be getting anywhere very quickly with that cadence! Assuming a 53x11 top gear, you be between 15 and 18mph when you were flat out!

I suppose "need" is the salient point, although I was chased by a rabid looking dog from a farm in Spain once, and I definitely needed to go quicker than that!

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Judge dreadful | 8 years ago
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Well it's nice to see some numbers to back up my theory, that amateur cyclists, who bang on about 'spinning' and 'cadence' are actually just making themselves look like demented Lycra clad hamsters  1 .

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vonhelmet replied to Judge dreadful | 8 years ago
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 45

Judge dreadful wrote:

Well it's nice to see some numbers to back up my theory, that amateur cyclists, who bang on about 'spinning' and 'cadence' are actually just making themselves look like demented Lycra clad hamsters  1 .

The report doesn't back that up in any way...

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Judge dreadful replied to vonhelmet | 8 years ago
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Errrrm yes it does.

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fukawitribe replied to Judge dreadful | 8 years ago
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Judge dreadful wrote:

Errrrm yes it does.

No, really it doesn't - have you actually read any of the paper, in particular the discussion and such things as muscular contraction efficiency as a function of pedal rate (which goes some way to possibly explaining the idea of 'natural cadence') ?

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Critchio | 8 years ago
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85 is good for me. In real world cycling us cycling enthusiasts or recreational cyclists can safely ignore this report. There's too many factors in play such as those wishing to lose weight, those with a dodgy knee, those on fixies, wind (tests done on static bikes), etc.

If it feels efficient it probably is. 85 to around 92 is my sweet spot, but if I have horrible head winds or I bonk this could be 75 and it still feels right. Business as usual.

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DaveE128 | 8 years ago
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I am by no means a pro cyclist (usually 40-70 miles a week, rides range from 40 mins to 5 hours, road and mtb.) but the figures quoted here are simply not relevant to my cycling and I doubt the selected conclusions picked out are either.

According to Strava estimates (yes, I know) I'm outputting average 200W most solo rides. I prefer to pedal at 95-115rpm most of the time, sometimes dropping to 85 min, because this is most comfortable. For me, this seems to manage fatigue well and gives me strong explosive power.

I doubt I ever produce 50 watts except when gently turning over a very high gear when going downhill, perhaps at 70rpm. If I put more power down the cadence goes right up and that's how I am most comfortable!

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peterrogers123 | 8 years ago
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Absolute rubbish, if you want to produce good power then work on high cadence, power = force x rpm.

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caaad10 | 8 years ago
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If you want to spin like Lance I think it helps to be on drugs, I find 80something to be quite fast enough, thank you very much.

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ChairRDRF | 8 years ago
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There are other reasons for avoiding a low cadence: it puts extra strain on joints and increases fatigue.

Also, in some situations there are advantages to expending energy (getting warmer/burning calories more swiftly when gas with staying with slower friends in a group).

I was told to spin more in my road-racing club because a higher cadence (generally 90+ on the flat, 80+ on a hill, up to about 105 and 95 respectively) allows you to accelerate more swiftly than a "slogger".

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TommyEss | 8 years ago
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But surely if you're a newby on an exercise bike then you're most likely exercising for weight loss etc - then "inefficiency" is extra energy, i.e. calories, burnt, so encourage them to pedal as fast as they can?!

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racyrich replied to TommyEss | 8 years ago
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TommyEss wrote:

But surely if you're a newby on an exercise bike then you're most likely exercising for weight loss etc - then "inefficiency" is extra energy, i.e. calories, burnt, so encourage them to pedal as fast as they can?!

Yes, and more pertinently (for me at least), if I do all my winter base miles on 63" fixed rather than rolling 52x18 around, will it improve my efficiency when pedalling fast? Or will it make my base miles less efficacious, my HR being higher than necessary for the power.

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fukawitribe replied to racyrich | 8 years ago
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racyrich wrote:
TommyEss wrote:

But surely if you're a newby on an exercise bike then you're most likely exercising for weight loss etc - then "inefficiency" is extra energy, i.e. calories, burnt, so encourage them to pedal as fast as they can?!

Yes, and more pertinently (for me at least), if I do all my winter base miles on 63" fixed rather than rolling 52x18 around, will it improve my efficiency when pedalling fast? Or will it make my base miles less efficacious, my HR being higher than necessary for the power.

If by base miles do you mean a lot of long, slow rides at lower intensities or just the filler/recovery stuff as part of something else ?

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racyrich replied to fukawitribe | 8 years ago
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fukawitribe wrote:
racyrich wrote:
TommyEss wrote:

But surely if you're a newby on an exercise bike then you're most likely exercising for weight loss etc - then "inefficiency" is extra energy, i.e. calories, burnt, so encourage them to pedal as fast as they can?!

Yes, and more pertinently (for me at least), if I do all my winter base miles on 63" fixed rather than rolling 52x18 around, will it improve my efficiency when pedalling fast? Or will it make my base miles less efficacious, my HR being higher than necessary for the power.

If by base miles do you mean a lot of long, slow rides at lower intensities or just the filler/recovery stuff as part of something else ?

Well, as per Base Building for Cyclists (Thomas Chapple), the initial part of base training should be at 55-75% of 30 minute power. Which is a rather broad range, but should encompass just about anything done on the flat on 63" fixed.

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CXR94Di2 | 8 years ago
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I have noticed that if I spin fast to make the power I have an elevated heart rate compared to lower revs(bigger gear)for the same power.

Obviously there is less fatigue to spin, just depends when you hit v 02 max

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antipathes | 8 years ago
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I don't actually think it's actually possible to spin at 110 rpm producing only 50 watts ( provided there is an actual chain on the bike  24 )
I would be interested to know the findings on anything between 200 to 400 watts for example.. It feels natural ( for me at least ) to increase cadence as power increases and vice versa..

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DrJDog | 8 years ago
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If you read the whole paper, you'll find that this aspect of it is a small part of the work, and they are just saying that to estimate oxygen usage you need to include RPM in the calculation as it can have quite a large effect on the result. They're not going into details about how efficient a club rider will be.

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CXR94Di2 | 8 years ago
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Horses for courses, when out on club run I tend to spin above 90rpm, on time trials I use 70 rpm. The latter allows me to develop the most power without hitting the max heart rate and blowing up.

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TeamExtreme | 8 years ago
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The 50W-110 rpm example is an extreme example used in the "Discussion" section of the paper to illustrate how "internal work rate" (i.e. effort required to move the limbs) correlates with "external work rate" (i.e. output power going through the drivetrain). They go on to say "In contrast, at elevated external power levels, the proportion of metabolic power associated with mechanical internal work rate becomes relatively smaller." This is all pretty obvious so far, everyone knows that spinning your legs with no resistance still requires energy and that as you add resistance (and thus increase output power) you wasted energy in terms of "internal work" will become relatively smaller.

The actual study monitored "16 combinations of external work rates (0, 50, 100, and 150 W) and [cadence] (50, 70, 90, and 110 revolutions per minute)" and measured VO2 at each level. They used this data to propose a new model for VO2 prediction that also includes cadence as a variable.

So essentially when you're doing your next trainer workout, instead of aiming for "10 min intervals @80% VO2max/whatever cadence you choose", you could be using this formula to work out what cadence you should be hitting to make your "80% VO2max" effort an accurate comparison.

I think the quotes from the author himself are a bit misleading here; increasing cadence may well be *less efficient* in terms of output power vs VO2 consumption, but in terms of actual real world cycling at low-to-moderate intensities, VO2 (and calorie consumption) are two of the factors that aren't usually a limiting factor; muscle fatigue from grinding round a massive gear will bite you in the ass first.

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Richard Hallett | 8 years ago
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'Formenti said that at very low intensities, a large proportion of the energy used in pedalling quickly goes on nothing more than spinning the legs.' This has been known for decades

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gonedownhill | 8 years ago
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Chris James | 8 years ago
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I wonder what they mean by 'recreational' cyclists? Club riders or just people who have ridden bike at some point in their lives?

Most beginner cyclists automatically pedal at about 60 rpm, but this tends to creep up over time as they get more experience (develop souplesse?).

Surely 50W is not really a very sensible power output to use when the object of the experiment is to estimate VO2 max? I very much doubt a pro would chose 110 rpm as a suitable cadence to develop 50 watts either!

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hawkinspeter | 8 years ago
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50W? I wanna know what wattage the high RPMs become effective.

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vonhelmet | 8 years ago
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How many of us are producing just 50 watts? I'm no Hoy, but even on my most relaxed rides Strava (I know... I know...) guestimates me at putting out over 100.

You'd have to be in the most ludicrously low gear to put out just 50W at 100+ rpm.

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pjclinch replied to vonhelmet | 8 years ago
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If you think how what proportion of Dutch commuters are bothering with Strava, that would kind of answer your question... The point of a bike is an efficient form of transport, which can mean going very fast for a high effort, or it can mean trundling along at little more than walking speed for practically no effort, or anywhere in between. Walking is usually about 60W, so anyone putting in walking-levels of energy rather than Going For It.

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surly_by_name replied to pjclinch | 8 years ago
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pjclinch wrote:

The point of a bike is an efficient form of transport...

Speak for yourself.

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